Diazotype reproduction materials



Sept. 30, 1969 J. KOSAR 3,469,981

DIAZO'IYPE REPRODUCTION MATERIALS Original Filed March 19, 1963 FIG.|

--- HEAT-DEVELOPABLE v TWO-COMPONENT PHOTOSENSITIVE ER l2 HEAT-DEV PABLETWO-COMPONENT PHOTO- SENSITWE ZOTYPE REPRODUCTION MATERIAL IO FIG.2

TWO- PONENT PHOTOS TIV DIAZOTYPE LAY 3 PRECOAT LAYER SUPPORT 2| ET-DEVELOPABLE TWO-COMPON T PHOTOSENSITIVE ZOTYPE REPRODUCTION MATE L 20FIG. 3 DEVELOPING SHEET so WHEAT'DECOMPOSABLE T AMIDE 32 suPPoRT 3|HEAT-DECOMPOSABLE AMIDE 32 -c0 s TWO-COMPONENT PHOTOSENSITIVE DIAZOTYPEREPRODUCTION MATERIAL 33 [NV OR. JAROMIR AR ATTORNEY United StatesPatent 3,469,981 DIAZOTYPE REPRODUCTION MATERIALS Jaromir Kosar,Bceehhurst, N.Y., assignor to Keuffel & Esser Company, Hoboken, N.J., acorporation of New Jersey Original application Mar. 19, 1963, Ser. No.266,230, new Patent No. 3,255,007, dated June 7, 1966. Divided and thisapplication July 12, 1965, Ser. No. 482,655

Int. Cl. G03c 1/58, 5/34 US. Cl. 96-49 24 Claims This is a division ofapplication Ser. No. 266,230, filed Mar. 19, 1963, now Patent No.3,255,007.

The present invention relates to diazotype reproduction materials and tomethods and means for their development, and refers more particularly toheat-developable diazotype reproduction materials and to methods andmeans for their development.

Diazotype reproduction materials are well known and have many advantagesover other means of reproduction when considering the combined bases ofquality and cost. However, they do possess some disadvantages which areinherent in the method of development.

Two methods of development are generally used: the semi-moist method andthe dry method, In the semimoist method the exposed diazotype materialis passed through a bath of coupler and squeezed dry. In the dry method,the exposed diazotype material is passed through a chamber of gaseousammonia to effect development.

The semi-moist method of development sutfers from the disadvantageousrequirements of periodic replenishment of the developer supply, removalof exhausted developer, periodic cleaning of developer container, anddeleterious effects of the liquid developer on the diazotype base whichis usually paper. The dry method has the disadvantages of requiringequipment to supply, confine, and exhaust the noxious ammonia.

Other means for developing diazotype materials have been tried but wereless practical than either the semimoist or dry methods.

Heat for example has been used to develop images on reproductionmaterials but they remained heat-sensitive and ultimately wereunsatisfactory as copies.

In an attempt to eliminate the disadvantages of both the semi-moist andthe dry developing systems, heat-development of diazotype reproductionmaterials was tried. This was feasible because exposure of a diazotypereproduction material through a master to a source of actinic radiationsdecomposes the diazonium compound in the non-image areas. Consequently,these areas cannot develop and the diazotype reproduction material ineffect is fixed or stabilized during exposure. The latent image couldthen be developed by some developing agent in the sensitized layer, in aseparate layer, or in a separate support.

For example, Dieterle in US. Patent 2,228,562 relates to a developingsheet treated with a heat-decomposable ammonia compound. Placed incontact with an exposed diazotype reproduction material and heated, thedeveloping sheet liberated ammonia vapors which developed the latentimage. The ammonia compounds, however, had very poor shelf-life andconsequently, their practical use was limited.

Barde in U.S. Patent 2,313,288 incorporated urea into a layer with adiazoic that formed its own coupler as a photolytic decompositionproduct. Heat decomposed the urea to liberate ammonia vapors which thenneutralized the acid formed during coupling. Morrison in US. Patent2,732, 299, on the other hand, incorporated urea into a separate stratumon the diazotype reproduction material to serve as the source ofheat-liberated ammonia.

Greig in US. Patent 2,691,587; Marron in US. Patent 2,774,669; andBenbrook in US. Patent 2,789,904

ice

all relate to developing sheets containing either the coupler or thesource of heat-liberated alkali.

Kendal et al. in British Patent 815,005 relates to multilayer diazotypereproduction material which comprised a support bearing a coupler layer,a fusible barrier layer, and a diazo layer.

Botkin in US. Patent 2,727,820 relates to an improvement in theproduction of photographic prints by the diazotype process whereincarboxamides were included in the photosensitive diazo layer to act asdeveloping aids when the diazotype reproduction material was developedin a conventional ammonia-developing machine.

The system of using developing sheets containing a source ofheat-liberated alkali avoided the disadvantages of liquid developers andof gaseous ammonia, but it introduced the inconvenience of a two-sheetsystem. The developing sheet had to be placed in uniform contact withthe exposed sensitized surface of the diazotype reproduction material toform a two-ply assembly which was then heated to effect development. Thedeveloping sheet was then separated from the reproduction material andset aside.

The major advantage of a developing sheet was the isolation of acritical ingredient until needed.

Isolation of the critical ingredient of the system could also beaccomplished by precoatings or multilayer coatings. This would overcomethe objection to the two-sheet system, but at the expense of increasedcost and increased technical difiiculty.

The simplest system was to coat all ingredients onto one support fromone solution in one layer in one operation. One requirement was thatboth the solution and the coated layer be stabilized to preventpremature coupling of the diazo compound and the coupler.

The present invention provides heat-developable twocomponentlight-sensitive diazotype reproduction materials, systems, and methods,which avoid the use of liquid developers and gaseous ammonia and whichare stable against further development. The invention is adaptable tothe developing sheet system, the precoat or multilayer system, and tothe single layer coating system.

One object of the present invention is to provide a heat-developablediazotype reproduction material, system, and method which does not havethe disadvantages of prior art.

Another object is to provide a heat-developable diazotype reproductionmaterial, system, and method which does not require the use of liquiddevelopers or gaseous ammonia for development.

Another object is to provide a heat-developable diazotype reproductionmaterial Which is stable against further color development.

Another object is to provide a heat-developable diazotype reproductionmaterial which is inexpensive and which gives good quality diazoreproductions.

Another object is to provide a heat-sensitive developing sheet for thethermal development of diazotype reproduction materials.

Another object is to provide a system which is adaptable to thetwo-sheet, the precoat, and the single layer systems of thermaldevelopment of diazotype reproduction materials.

Other objects of the present invention will become apparent in thecourse of the following specification.

In the present invention, thermally decomposable sources of alkali areused as developing agents for the diazotype reproduction material. Thesesources of alkali are organic nitrogen compounds which may be classifiedas amides. Depending upon their chemical nature, they may be used in thesensitized layer, in a precoated layer, or in a separate developingsheet. Thus these amides can be used in at least three diazotypereproduction systems.

The amides of the present invention are decomposed at elevatedtemperatures when it is desired to release ammonia. This raises thealkalinity of the sensitized layer and allows coupling to occur and thusrenders the latent image visible.

Some of the amides found to be suitable for the present invention arethose derived from monobasic saturated acids, mono-basic unsaturatedacids, aromatic carboxylic acids, aromatic hydroxy acids, saturateddibasic acids, and aromatic dibasic acids. These amides have the generalformula:

where R is hydrogen, alkyl, substituted alkyl, alkylene, substitutedalkylene, amidated alkyl, aryl, substituted aryl, amidated aryl, aheterocyclic ring, or a polymeric chain, and

NH2 n where there is at least one amido group per monomer unit for thisamidated polymer thain; n is preferably approximately 560.

Amides are derived from carboxylic acids by replacing the OH group withan NH group or NR R group where R and R may be hydrogen, alkyl, or aryl.The amides are generally solids at room temperatures; the lowermolecular weight amides being readily soluble in water, while the highermolecular weight amides are almost insoluble in water.

By heating in the presence of acids, the amides are bydrolyzed tocarboxylic acids with consequent liberation of alkaline vapors. Thesealkaline vapors are utilized to develop the exposed diazotypereproduction material. The presence of acid is not required foroperation of the invention. This is demonstrated by Example 17 andothers.

Combinations of diazonium compounds and couplers that are suitable forthe conventional dry developing diazotype reproduction materials can beemployed in the present invention. Examples of the diazonium compoundsare the zinc chloride and the boron trifluoride stabilized salts ofp-dialkylamino benzene diazonium chlorides. These compounds are used inconcentrations ranging from 1.5 to of the sensitizing solution, and theycan be used singly or in combinations.

Some suitable couplers are phenols and naphthols, such asphloroglucinol, resorcinol, alpha-naphthol, betanaphthol, and2,3-dihydroxynaphthalene-6 sulfonic acid (sodium salt). These couplersmay be used singly or in combination to vary the color.

The coating solution and the sensitized layer can also contain variousother chemicals commonly used in the preparation of light-sensitivediazotype reproduction materials. These include stabilizing acids,anti-oxidants, hygroscopic agents, wetting agents, and imageintensifiers.

Acids that can be used are tartaric acid, citric acid, acetic acid,trichloroacetic acid, and 1,3,6-naphthlenetrisulfonic acid or its sodiumsalt.

Thiourea and allyl isothiocyanate are commonly used anti-oxidants.

The sensitizing solution and sensitized layer may further containhygroscopic agents such as glycerine, ethylene glycol, or the like;wetting agents such as saponin and lauryl sulfonates; and imageintensifiers such as Zinc chloride and nickel sulfate.

The coating solution is applied in a conventional manner to a suitablesupport, the excess removed, and the coating dried. Suitable supportsinclude not only those types of papers such as ordinary pulp paper, ragpaper, and document paper, but also starch filled cloth, felt,saponified cellulose acetate film, transparent cellulosic material suchas cellophane, and the like. In the drawmgs:

FIGURE 1 is a sectional view of a heat-developable two-componentphotosensitive diazotype reproduction material 10 of the presentinvention comprising a support 11 and a heat-developable two-componentphotosensitive diazotype layer 12 coated on said support;

FIGURE 2 is a sectional view of a heat-developable two-componentphotosensitive diazotype reproduction material 20 of the presentinvention comprising a support 21, a precoat layer 22 coated on saidsupport, and a two-component photosensitive diazotype layer 23 coatedover said precoat layer on said support; and

FIGURE 3 is a sectional view of a developing sheet 30 comprising asupport 31 and a heat-decomposable amide 32 impregnated in support 31,in juxtaposition with a two-component photosensitive diazotypereproduction material 33 comprising a support 34 and a two-componentphotosensitive diazotype layer 35 coated on support 34.

One method of the present invention for the preparation of aheat-developable reproduction material is to first treat a supportmaterial with a solution of an amide. After drying, the same support istreated on the same side or on the opposite side with a sensitizingsolution containing as major ingredients: a diazonium compound, acoupler, and where desired, a stabilizing acid. After drying, thesensitized support is ready for use. The sensit zed support is exposedthrough a master to actinic radiatrons and is then developed by heat inthe range between the decomposition temperature of the amide and thescorching temperature of the support material. The heat-activatedliberation of alkaline vapors then causes the image to develop.

The preparation and use of a heat-developable twocomponentphotosensitive diazotype reproduction material precoated with an amideof the present invention is illustrated in Example 1.

In another method of preparation of the present invention, the amide isincorporated with the photosensitive diazonium compound, a coupler, andwhere desired, a stabilizing acid in a sensitizing solution which isapplied to a support and then dried. The sensitized support can then beexposed through a master to actinic radiations. After exposure, heat isapplied to the support. The temperature is preferably in the rangebetween the decomposition temperature of the amide and the scorchingtemperature of the support material. This method of preparation isillustrated in Example 2.

A developing sheet was prepared by impregnating a support with asolution of an amide in an appropriate solvent. The solvent was thenremoved by drying. The developing sheet was then used to develop anexposed two-component photosensitive diazotype reproduction material bymaking face-to-face contact with the exposed sensitized surface of thediazotype material and subjecting the assembly to heat in the rangebetween the decomposition temperature of the amide and the scorchingtemperature of the diazotype support. Alkaline vapors were liberated toelfect development of the latent image. The preparation and use of adeveloping sheet utilizing an amide of the present invention isillustrated in Example 3.

As an alternative procedure, the alkali-liberating agent may beincorporated into the pulp or raw material used to manufacture thesupport in suitable proportions to obtain the desired results.

The developing temperature range was determined by two factors: thefirst was the decomposition temperature of the thermally decomposableamide, and the second was the scorching temperature of the support. Thedecompo sition temperature of the thermally decomposable amide isaffected by the presence of other chemicals in the system. The presenceof a good source of hydrogen ions favors decomposition by hydrolysis.

The following examples further illustrate the present invention and arenot intended to restrict or limit the scope of the invention.

Example 1 30 grams of acrylamide were dissolved in 150 milliliters ofwater and were coated onto a paper support. After drying, the precoatedsupport was sensitized with the following solution:

The coating was dried to produce a precoated and sensitized diazotypereproduction material. This was exposed through a master to actinicradiations and developed by subjecting the reproduction material to 150C. for a few seconds. The heat liberated alkaline vapors from the amideand allowed the diazonium compound and the coupler to form a blue dyeimage corresponding to the master image.

No liquid developer or gaseous ammonia was required for development. Inaddition the developed reproduction material was stable against furtherdye formation under the influence of heat. This precoating system wasparticularly suitable for amides which were not water-soluble or whichwere not compatible with the chemicals in the sensitizing solution.

Example 2 A sensitizing solution according to the following formula wasprepared and coated on a conventional silicasized diazotype papersupport:

Water, ml. 4,500

The coating was dried to produce a heat-developable diazotypereproduction material. This was exposed through a master to actinicradiations and then subjected to heat in the range of C. to thescorching point of the paper support for a few second to liberatealkaline vapors and thus develop the blue dye image corresponding to themaster image.

This system and method was preferred whenever the water solubility andthe chemical compatibility of the amide with the other chemicalspermitted incorporation into a single solution. Diazonium compoundsother than p-dimethylamino benzene diazonium chloride can be used, c.g.,p-diethylamino benzene diazonium chloride, andN-ethyl-N-(2hydroxyethyl)-p-amino benzene diazonium chloride were alsoused. Another coupler such as phloroglucinol was also used.

Example 3 20 grams of acrylamide were dissolved in 100 ml. of ethylalcohol. This solution was used to impregnate a porous paper support.After drying, a developing sheet for the heat-development of exposedtwo-component diazotype reproduction materials was produced. On aseparate paper support the sensitizing solution of Example 1 was appliedand dried. This was exposed through a master to actinic radiations anddeveloped by making face-to-face contact with the developing sheet andsubjecting the whole assembly to C. for 5 seconds. A blue dye imagecorresponding to the master image was produced without benefit of liquiddeveloper or gaseous ammonia. The print was stable against any furtherdye formation due to the application of heat.

This system was ideal for amides which were not compatible with thechemicals of the sensitizing solution since isolation was complete. Inprinciple, this isolation can also be achieved by the multilayer systemdescribed in British Patent 815,005 and by microencapsulation of thedeveloping agent or the coupler.

These first three examples demonstrate the fact that an amide can beused in three dilferent systems as the source of alkali for theheat-development of diazotype reproduction materials.

Example 4 The following sensitizing solution was prepared and coated ona support. After the coating was dried, the sensitized support wasexposed to actinic radiation through a master and developed bysubjecting it to heat. The color of the image was blue.

Formamide, g. 10

Example 5 A coating of the following diazo sensitizing solution wasapplied to a paper support:

Water, ml. 150 p-Dimethylamino benzene diazonium chloride, zinc chloridesalt, g 4 2,3-dihydroxynaphthalene 6 sulfonic acid, sodium salt, g. 5Thiourea, g. 7 Zinc chloride, g. 4

An absorbent sheet was soaked with the following solution:

Etthyl alcohol, ml. 100 N,N-diphenylfor mamide, g. 10 Trichloroaceticacid, g. 5

After drying, the developing sheet was brought into uniform contact withthe sensitized paper which had been exposed through a master to actinicradiations. The assembly of developing sheet and the diazo sensitizedpaper was then heated at 150 deg. C. for seconds to produce a blue imageon the diazo sensitized paper corresponding to the master image.

Example 6 The following sensitizing solution was coated on a supportsuitable for diazotype reproduction materials:

Water, ml. 150 Trisodium salt of 1,3,6-na1phthalene trisulfonic acid, g.6 p-Dimethylamino benzene diazonium chloride, zinc chloride salt, g. 4Sodium salt of 2,3-dihydroxynaphthalene-6-sulfonic acid, g. 5 Thiourea,g. Zinc chloride, g. 4 Acetamide, g. 30

pH adjusted to 3.4 with trichloroacetic acid.

The sensitized support was then dried and exposed through a master toactinic radiation. Heat was used to develop the latent image as a bluedye image.

Example 7 To improve storage life, trichloroacetic acid was addedaccording to the following formula:

Water, ml. 150 Tartaric acid, g /2 Trisodium salt of 1,3,6-naphthalenetrisulfonic acid, g. 6 p-Dimethylamino benzene diazonium chloride, zincchloride salt, g. 4 Acetamide, g. 30 Sodium salt of2,3-dihydroxynaphthalene-6-sulfonic acid, g. 5 Thiourea, g. 10 Zincchloride, g. 4 Trichloroacetic acid, g. 5

The pH of the solution was 1.3. Storage life was improved by theaddition of trichloroacetic acid. Material stored at 115 deg. F. and 47%relative humidity for three days still produced acceptable andsatisfactory prints. Lesser amounts of trichloroacetic acid reduced thestorage life of the sensitized reproduction material.

Example 8 The following sensitizing solution was prepared and coated ona support suitable for diazotype reproduction materials on a productionrun basis:

The coating speed was 16 yards per minute with an airbar pressure of 3/2 oz. of water. The drying temperature was 180 F.

The sensitized and dried material was then exposed through a master toactinic radiation and developed by the application of heat. Thedeveloped image was blue in color and satisfactory in density.

Example 9 A support sheet was pre-coated with the following solution:

Water, ml. Acetamide, g. 30

After drying, the precoated support was sensitized with the followingsensitizing solution:

Water, ml. 150 Trisodium salt of 1,3,6-naphthalene trisulfonic acid, g.6 Trichloroacetic acid, g. 5 p-Dimethylamino benzene diazonium chloride,zinc chloride salt, g. 4 Sodium salt of2,3-dihydroxynaphthalene-6-sulfonic acid, g. 5 Thiourea, g. 7 Zincchloride, g 4

The pH of the sensitizing solution was 1.0. After drying, the sensitizedsheet was exposed through a master to actinic radiations and developedby heating at 150 C. for 4 seconds. A blue image corresponding to themaster image was obtained.

Example 10 An absorbent base sheet was soaked in a solution containing10 grams of acetamide in 150 ml. of ethyl alcohol and then dried toremove the alcohol to produce a developing sheet.

A paper support was sensitized with the following solution:

Water, ml. 150 Trisodium salt of 1,3,6-naphthalene trisulfonic acid, g.6 Trichloroacetic acid, g. 5 p-Dimethylamino benzene diazonium chloride,zinc chloride salt, g. 4 Sodium salt of2,3-dihydroxynaphthalene-6-sulfonic acid, g. 5 Thiourea, g. 7 Zincchloride, g 4

After drying, the developing sheet and the exposed sensitized supportwere placed in contact and heated at 150 C. for a few seconds to producea blue image corresponding to the master image.

Example 11 The following solution was prepared and coated on anabsorbent support to form a developing sheet:

Ethyl alcohol, ml. 25 Trichloroacetic acid, g. 1 Phenoxyacetamide, g.2.5

Heating this sheet in contact at 175 C. for 5 seconds with a printed butundeveloped diazotype paper such as that described in Example 10produced a brown image.

Example 12 A developing sheet prepared by coating the following solutionon an absorbent support when heated in contact with printed diazotypepaper as described in Example 10 caused a blue image to be produced onthe diazotype paper:

Ethyl alcohol, cc. 100 Trichloroacetic acid, g 3 N,N-diphenylacetamide,g. 10

Contact time was 6 seconds at C.

9 Example 13 The following solution was prepared and coated in anabsorbent support:

Water, cc. 150 Propionamide, g. 30 1,3,6-naphthalene trisulfonic acid,trisodium salt, g. 6 Trichloroacetic acid, g.

p-Dimethylamino benzene diazonium chloride, zinc chloride salt, g. .2 42,3 dihydroxynaphthalene-6-sulfonic acid, soduim salt, g. 5 Thiourea, g.7 Zinc chloride, g. 4

After printing through a master, the blue image was developed by heatingfor 5 second at 150 C.

Example 14 Propionamide was used in the following solution to prepare adeveloping sheet:

Water, cc. 100 Trichloroacetic acid, g. 2 Propionamide, g. 5

When used to develop a printed diazotype paper such as that described inExample 10, a blue image was obtained. Contact time was 5 seconds at 150C.

Example 15 The following chemicals were substituted individually for thepropionamide in Example 13 with the result that the developed imageswere substantially the same as for propionamide:

n-Butyramide iso-Butyramide n-Valeramide iso-Valeramide Example 16Hexanamide, nonanamide, and stearamide were used separately in thefollowing solution formula to prepare developing sheets:

Ethyl alcohol, cc. 50 Trichloroacetic acid, g. 1.5 Amide, g. 5

When these developing sheets were used to develop printed diazotypesheets prepared as described in Example 10, blue images were obtained.Contact time was 5 seconds at 160 C.

Example 17 The sensitizing solution was prepared with acrylamideaccording to the following formula:

Water, cc. 100 p-Diethylamino benzene diazonium chloride, zinc chloridesalt, g. 4

2,3 dihydroxynaphthalene-6-sulfonic acid, sodium salt, g. 5 Acrylamide,g. 50

This solution was coated on an absorbent support and dried. Whenheat-developed at 150 C. for 5 seconds a blue color was developed.

Example 18 Polyacrylamide of low molecular weight such as PAM was usedin the following sensitizing solution:

Water, cc. 100 Polyacrylamide PAM 10, g. 50 Trichloroacetic acid, g. 81,3,6-naphthalene trisulfonic acid, trisodium salt, g. 6 p-Dimethylaminobenzene diazonium chloride, zinc chloride salt, g. 4

10 2,3 dihydroxynaphthalene-6-sulfonic acid, sodium salt, g. 5 Thiourea,g. 7 Zinc chloride, g 4

This solution was coated on an absorbent support and was dried. Afterprinting with ultraviolet light through a master, the image wasdeveloped by heating the coated support at 150 C. for 5 seconds.

Example 19 Polyacrylamide such as PAM 10 was used in the followingsolution to prepare a precoat solution:

Water, cc. Polyacrylamide PAM 10, g. 50 Trichloroacetic acid, g. 10

This solution was coated on a support and dried. The precoated paper wasthen sensitized with a solution such as described in Example 1. Heattreatment after exposing the sensitized support through a masterproduced a blue dye image.

Example 20 The same polyacrylamide solution as in Example 19 was used tocoat an absorbent support to make a developing sheet. When used as inExample 3 to develop a diazotype paper by placing it in contact with theexposed diazotype paper and heating the assembly for a few seconds at C.a blue image on the diazotype paper was developed.

Example 21 Hexamethylene-bis-acrylamide was used to prepare a solutionaccording to the following formula:

Ethyl alcohol, cc 100 Hexamethylene-bis-acrylamide, g. 10Trichloroacetic acid, g. 5

This solution was used to impregnate an absorbent sup port. Afterdrying, this developing sheet was placed in contact with sensitized andexposed diazotype paper and heated at 150 C. for 8 seconds. A blue imagewas formed.

Example 22 Methacrylamide was used in place of the acrylamide ofExamples 2 and 17, with the same results.

Example 23 Malonamide was used in the following sensitizing solu- 2,3dihydroxynaphthalene-d-sulfonic acid, sodium salt, g. 5 Thiourea, g. 7Zinc chloride, g 4 Development of a blue dye image after exposure was accomplished by heating at C. for 4 seconds.

Example 24 Benzamide was used in the following solution to prepare adeveloping sheet:

Ethyl alcohol, cc 100 Benzamide, g. 5

This solution was then used to impregnate an absorbent support. Heatingthe developing sheet while it was in contact with a diazotype paperprepared as in Example 5 resulted in development of a blue color on thediazotype sheet.

Example 25 The solution of Example 24 was used also as a precoatsolution. It was coated on a support, dried, and then sensitized withthe following solution on the same side:

Water, cc. 150 1,3,6-naphthalene trisulfonic acid, trisodium salt, g. 6Tartaric acid, g. /2 p-Dimethylamino benzene diazonium chloride, zincchloride salt, g. 4 2,3-dihydroxynaphthalene-6-sulfonic acid, sodiumsalt, g Thiourea, g. 7 Zinc chloride, g. 4

After exposure through a master, a blue dye image was developed byheating the exposed sheet for 5 seconds at 150 C.

Example 26 p-Toluamide was used in the following solution to prepare adeveloping sheet:

Ethyl alcohol, cc. 50 p-Toluamide, g. 5 Trichloroacetic acid, g. 1.5

The developing sheet was used to develop diazotype paper prepared as inExample 5. A blue color was developed by heating the developing sheet incontact with the diazotype paper for a few seconds at 165 C.

Example 27 p-Nitrobenzamide was used in the following solution toprepare a developing sheet:

Ethyl alcohol, cc. 25 p-Nitrobenzamide, g. 2.5 Trichloroacetic acid, g.1.0

This developing sheet was used to develop a red-brown dye color in thesame manner as in Example 26.

Example 28 Anthranilamide was used in the following solution to preparea developing sheet:

Ethyl alcohol, cc 100 Anthranilamide, g Trichloroacetic acid, g. 5

This solution was coated on a support to make a developing sheet whichthen was used to develop a diazotype paper as described in Example 5 toproduce a blue dye image.

Example 29 Anthranilamide was also used in the following sensitiz- Thiswas coated on a support and dried. Heating the exposed sensitized sheetat 160 C. for 6 seconds produced a blue dye image.

Example 30 Phthalamide :was used to make a developing sheet by coating asupport with the following solution:

Ethyl alcohol, cc 100 Phthalamide, g. 5 Trichloroacetic acid, g, 2.5

Placing this developing sheet in contact with a printed diazotype paperand subjecting the assembly to heat at 175 C. for several secondsproduced a blue image.

Example 31 Salicylamide was used in a developing sheet prepared bycoating a support with the following solution:

Ethyl aclohol, cc. Salicylamide, g. 5

The developing sheet was used to develop a blue dye image as in Examples5 and 30.

Example 32 Salicylamide was also used in a precoat layer by coating asupport with the following solution:

Ethyl alcohol, cc Salicylamide, g. 10

The precoated support was then sensitized as in Example 9. Afterexposure through a master to actinic radiations, a blue color wasdeveloped by heating the sensitized precoated support for 5 seconds at150 C.

Example 33 Z-furamide was used in the following solution to coat asupport to a make a developing sheet:

Ethyl alcohol, cc. 50 2-furamide, g. 5 Trichloroacetic acid, g 1.5

This developing sheet was used at 175 C. for 4 seconds to developprinted diazotype paper as described in Example 5.

Example 34 N-methylacetamide was used to prepare a developing sheet byimpregnating an absorbent support with the following solution:

Ethyl alcohol, cc. 25.0 N-methylacetamide, g. 2.5 Trichloroacetic acid,g 1.0

After drying, this developing sheet was used to develop exposeddiazotype paper prepared as in Example 5 by placing the two sheets incontact and heating them at C. for 7 seconds to obtain a blue color.

Example 35 Example 34 was repeated with 2-phenylacetamide in place ofN-methylacetamide. After following the same procedure, a blue greenimage was obtained.

Example 36 Nicotinamide was used in the following solution to impregnatean absorbent support to make a developing sheet:

Water, cc. 50 Nicotinamide, g. 5

This sheet was then dried and used to develop an exposed diazotype paperby placing it in contact with the exposed diazotype paper and heatingthe assembly at 150 C. for 6 seconds to obtain a colored image.

Example 37 A support was precoated with the following solution:

Water, cc. 50 Nicotinamide, g. 5 Trichloroacetic acid, g. 2

13 After drying, the precoated support was sensitized with the followingsolution:

After drying, the sensitized support was exposed through a master toactinic radiations and then developed by heating at 160 C. for seconds.A blue-black image was obtained.

It is apparent that the described examples are capable of manymodifications and variations with the scope of the present invention.All such modifications and variations are to be included :within thescope of the present invention.

What is claimed is:

1. A process for forming an azo dye comprising:

(a) placing in face-to-face combination:

(1) a two-component diazotype sheet material comprising a diazoniumcompound and an azo dye coupler capable of forming an azo dye with saiddiazonium compound in an alkaline environment; and

(2) a developer sheet comprising a support, and

an alkali-liberating amide thermally-decomposable at a temperature belowthe scorching temperature of said support and having the general formulawherein R is hydrogen, alkyl, alkylene, aryl or an amidated polymericradical having a molecular weight of about 40,000, and R and R are,individually, hydrogen, alkyl or aryl; and

(b) heating said combination to atemperature between the decompositiontemperature of said amide and the scorching temperature of said support.

2. A process for forming a diazotype image comprising:

(a) imagewise exposing to actinic radiation diazotype sheet materialcomprising a light-sensitive diazonium compound and an azo dye couplercapable of forming an azo dye with said diazonium compound in analkaline environment;

(b) placing said diazotype material in face-to-face contact with adeveloper sheet comprising a support, and an alkali-liberating amidethermally-decomposable at a temperature below the scorching temperatureof said support and having the general formula wherein R is hydrogen,alkyl, alkylene, aryl or an amidated polymeric radical having amolecular weight of about 40,000, and R and R are, individually,hydrogen, alkyl or aryl; and

(c) heating said combination to a temperature between the decompositiontemperature of said amide and the scorching temperature of said support.

3. A process according to claim 1 wherein said developer sheet furthercomprises an organic acid in an amount between about 20% and 50% of theamount of amide.

4. A process according to claim 3 wherein said acid is trichloraceticacid.

5. A process according to claim 2 wherein said developer sheet furthercomprises an organic acid in an amount between about 20% and 50% of theamount of amide.

6. A process according to claim 5 wherein said acid is trichloroaceticacid.

7. A process according to claim 1 wherein said amide is acrylamide.

8. A process according to claim 1 wherein said amide is N,N-diphenylformamide.

9. A process according to claim 1 wherein said amide is acetamide.

10. A process according to claim 1 wherein said amide isphenoxyacetamide.

11. A process according to claim 1 wherein said amide isN,N-diphenylacetamide.

12. A process according to claim 1 wherein said amide is stearamide.

13. A process according to claim 1 wherein said amide is polyacrylamide.

14. A process according to claim 1 wherein said amide ishexamethylene-bis-acrylamide.

15. A process according to claim 1 wherein said amide is benzamide.

16. A process for the thermal development of twocomponentlight-sensitive diazotype reproduction materials, by means of adeveloping sheet, said reproduction material comprising a support and alight-sensitive layer coated on said support, said developing sheetcomprising a separate support and a thermally decomposablealkaliliberating developing agent impregnated in said separate support,said developing agent being N,N-diphenyl formamide, said processcomprising the steps of: (1) exposing said reproduction material toactinic radiations through a master, (2) separating the reproductionmaterial from the master, (3) making an assembly with the developingsheet in uniform contact with the sensitized surface of saidreproduction material, and (4) heating the assembly in the temperaturerange between the decomposition temperature of the developing agent andthe scorching temperature of said reproduction material support, thusliberating alkali in the immediate vicinity of the sensitized surface ofsaid reproduction material, thereby causing coupling to occur in theimage areas.

17. A process for the thermal deveopment of two-componentlight-sensitive diazotype reproduction materials by means of adeveloping sheet, said reproduction material comprising a support and alight-sensitive layer coated on said support, said developing sheetcomprising a separate support and a thermally decomposablealkali-liberating developing agent impregnated in said separate support,said developing agent being acetamide, said process comprising the stepsof: (1) exposing said reproduction material to actinic radiationsthrough a master, (2) separating the reproduction material from themaster, (3) making an assembly with the developing sheet in uniformcontact with the sensitized surface of said reproduction material, and(4) heating the assembly in the temperature range between thedecomposition temperature of the developing agent and the scorchingtemperature of said reproduction material support, thus liberatingalkali in the immediate vicinity of the sensitized surface of saidreproduction material, thereby causing coupling to occur in the imageareas.

18. A process for the thermal development of two-componentlight-sensitive diazotype reproduction materials by means of adeveloping sheet, said reproduction material comprising a support and alight-sensitive layer coated on said support, said developing sheetcomprising a separate support and a thermally decomposablealkali-liberating developing agent impregnated in said separate support,said developing agent being phenoxyacetamide, said process comprisingthe steps of: 1) exposing said reproduction material to actinicradiations through a master, (2) separting the reproduction materialfrom the master, (3) making an assembly with the developing sheet inuniform contact with the sensitized surface of said reproductionmaterial, and (4) heating the assembly in the temperature range betweenthe decomposition temper- 1 ature of the developing agent and thescorching temperature of said reproduction material support, thusliberating alkali in the immediate vicinity of the sensitized surface ofsaid reproduction material, thereby causing coupling to occur in theimage areas.

19. A process for the thermal development of two-componentlight-sensitive diazotype reproduction materials by means of adeveloping sheet, said reproduction material comprising a support and alight-sensitive layer coated on said support, said developing sheetcomprising a separate support and a thermally decomposablealkali-liberating developing agent impregnated in said separate support,said developing agent being N,N-diphenylacetamide, said processcomprising the steps of: (1) exposing said reproduction material toactinic radiations through a master, (2) separating the reproductionmaterial from the master, (3) making an assembly with the developingsheet in uniform contact with the sensitized surface of saidreproduction material, and (4) heating the assembly in the temperaturerange between the decomposition temperature of the developing agent andthe scorching temperature of said reproduction material support, thusliberating alkali in the immediate vicinity of the sensitized surface ofsaid reproduction material, thereby causing coupling to occur in theimage areas.

20. A diazotype developer sheet comprising:

(a) a support;

(b) an alkali-liberating amide thermally-decomposable at a temperaturebelow the scorching temperature of said support and having the generalformula wherein R is hydrogen, alkyl, alkylene, aryl or an amidatedpolymeric radical having a molecular 16 Weight of about 40,000, and Rand R are, individually, hydrogen, alkyl or aryl; and (c) an organicacid in an amount between about 20% and of the amount of amide. 21. Adeveloper sheet according to claim 20 wherein said acid istrichloroacetic acid.

22. A developer sheet according to claim 20 wherein said amide isacetamide.

23. A developer sheet according to claim 20 wherein said amide isstearamide.

24. A developer sheet according to claim 20 wherein said amide isacrylamide.

References Cited UNITED STATES PATENTS 2,358,871 9/1944 Maxwell 117-1542,687,958 8/1954 Neugebauer 96-93 X 2,727,820 11/1955 Botkin 96-492,774,669 12/1956 Marron et al. 9649 3,206,311 9/1965 Campbell et al.117-154 X 3,224,902 12/1965 Sodler et al. 117-154 X 3,244,734 4/1966Sommtag 117-154 X 2,653,091 9/1953 Greig 96-49 3,203,797 8/1965 Muller96-49 FOREIGN PATENTS 816,601 7/1959 Great Britain. 459,141 8/ 1949Canada.

I. TRAVIS BROWN, Primary Examiner O. BOWERS, Assistant Examiner U.S. Cl.X.R.

1. A PROCESS FOR FORMING AN AZO DYE COMPRISING: (A) PLACING INFACE-TO-FACE COMBINATION: (1) A TWO-COMPONENT DIAZOTYPE SHEET MATERIALCOMPRISING A DIAZONIUM COMPOUND AND AN AZO DYE COUPLER CAPABLE OFFORMING AN AZO DYE WITH SAID DIAZONIUM COMPOUND IN AN ALKALINEENVIRONMENT; AND (2) A DEVELOPER SHEET COMPRISING A SUPPORT, AND ANALKALI-LIBERATING AMIDE THERMALLY-DECOMPOSABLE AT A TEMPERATURE BELOWTHE SCORCHING TEMPERATURE OF SAID SUPPORT AND HAVING THE GENERAL FORMULA2. A PROCESS FOR FORMING A DIAZOTYPE IMAGE COMPROSING: (A) IMAGEWISEEXPOSING TO ACTINIC RADIATION DIAZOTYPE SHEET MATERIAL COMPRISING ALIGHT-SENSITIVE DIAZONIUM COMPOUND AND AN AZO DYE COUPLER CAPABLE OFFORMING AN AZO DYE WITH SAID DIAZONIUM COMPOUND IN AN ALKALINEENVIRONMENT; (B) PLACING SAID DIAZOTYPE MATERIAL IN FACE-TO-FACE CONTACTWITH A DEVELOPER SHEET COMPRISING A SUPPORT, AND AN ALKALI-LIBERATINGAMIDE THERMALLY-DECOMPOSABLE AT A TEMPERATURE BELOW THE SCORCHINGTEMPERATURE OF SAID SUPPORT AND HAVING THE GENERAL FORMULA
 20. ADIAZOTYPE DEVELOPER SHEET COMPRISING: (A) A SUPPORT; (B) ANALKALI-LIBERATING AMIDE THERMALLY-DECOMPOSABLE AT A TEMPERATURE BELOWTHE SCORCHING TEMPERATURE OF SAID SUPPORT AND HAVING THE GENERAL FORMULA